PostGIS is an extension for the PostgreSQL object-relational database that adds support for geographic objects.
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12 views
Units of Geometry & Geography data type [duplicate]
When you store data using the Geography data type (like in PostGIS), is it always in lon/lat in degree decimals?
For the Geometry data type, what are the units used in the coordinate pairs? Can it ...
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1answer
42 views
Finding route contains Source and Destination points
I have a problem with finding routes that are near (in range X km) the passed points (for e.x. A and B) in PostgreSQL PostGIS.
Example:
The point A denotes Source point and The point B denotes the ...
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1answer
48 views
problems about setting pgrouting with QGIS under windows
I followed this website：A Beginner’s Guide to pgRouting and now facing some problems.
I finished steps before "Creating a routable road network", and open QGIS 1.8, click the PostGIS Manager plugin, ...
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1answer
91 views
How to split line layer at polygons' boundary of a polygon layer?
I have a line layer and a polygon layer in PostgreSQL 9.2, PostGIS 2.0. How can I split every line each time it crosses a polygon's boundary?
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1answer
60 views
How do I get the closest distance for each element within a point coordinate table from a polyline table?
Postgres: How do I get the closest distance for each element within a point coordinate table from a polyline table? And if this is possible what version of Postgres is this doable.
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2answers
160 views
What Spatial Reference System do I store Google Map's Lat/Lng in
I am new to PostGIS, Spatial Reference Systems and projections and want to store lat/lng coordinates retrieved from Google Maps and Openstreetmap and its services like the Geocoder/Nominatim. I'm ...
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1answer
99 views
What Spatial Reference System do I store Google Map's Lat/Lng in [duplicate]
I am new to PostGIS, Spatial Reference Systems and projections and want to store lat/lng coordinates retrieved from Google Maps and its services like the Geocoder. I'm working with data in America and ...
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2answers
55 views
Where can I get public transportation locations for USA
I am trying to find a list of all public transportation/transit locations like subway stations, airports, bus terminals and bus stops for USA. Only major transit locations are required, rural bus ...
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1answer
64 views
How to perform SIA or Bezier line smoothing in PostGIS?
Can anyone provide an example SQL for smoothing linestrings from postgis table using Bezier curves or Iterative Averaging (SIA) algorithm?
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1answer
65 views
Diff operation in PostGIS/Geotools
What is the best way to perform a diff operation on Postgis features/tables or Geotools objects? Are there any automatic methods I can use? If not, what would be the optimal way to implement your own ...
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1answer
50 views
ST_Box2D in PostGIS 2.0
I am getting an error trying to create a bounding box of a geometry using ST_Box2D(). Is the function deprecated? If so, what is the equivalent function?
SELECT ST_Box2D(ST_GeomFromText('LINESTRING(1 ...
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1answer
73 views
Value at a particular spot on Geoserver Heatmap
Geoserver is drawing from a PostGIS database to generate a heatmap using this SLD extension. Leaflet then overlays the heatmap over the base layer.
Question: How can you determine the value at a ...
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2answers
63 views
Manually add a new point to PostGIS table [duplicate]
I did accidently delete a table row - or well, in fact a whole subway station.
My attempt to solve the problem was this PostGIS function:
ST_GeomFromText('POINT(coordinates)')
But then PostgreSQL ...
7
votes
1answer
172 views
Generating Heatmap from PostGIS
I have GIS data in a PostGIS data base and would like to generate a density map and display them on a Leaflet/Google Maps.
Question: What is the recommended/typical method for doing so, without ...
2
votes
1answer
88 views
Need help assigning values to field using OGR in python
I've got a similar question to this one How to programatically populate a shapefile field with polygon areas in OGR?, but the solution doesn't seem to be working for me. I am trying to import a ...
2
votes
1answer
96 views
How to get the coastline from OSM?
I've successfully imported all data for Sweden to my PostGIS database. Right now I'm designing my map in Tilemill with OSM Bright as base.
But I've got a major problem: where is the coastline? Right ...
2
votes
1answer
67 views
ST_Equals Postgis problems
I am trying to find overlapping lines using ST_EQUALS on two tables
This query returns 0 rows:
SELECT * FROM geom1 c, geom2 h WHERE st_equals(c.simple_geom, h.simple_geom);
This query runs ...
3
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0answers
53 views
Where can I find PostGIS error codes?
Using ST_Contains in where clause sometimes gives me error messages like
ERROR: GEOSContains: TopologyException: side location conflict at 37.3706 55.7882
For now I can't guarantee validity for ...
3
votes
1answer
109 views
Postgis: aggregate function for intersection
I have a PostGIS Table with LINESTRINGS.
I like to a query that returns all Roads that are connected.
So I get a set of unconnected trees (in german 'Wald (Graphentheorie)')
pseudo code:
select ...
2
votes
1answer
53 views
Regenerate Geowebcache Tiles on PostGIS change
I am using Geoserver with Geocache to get WMS tiles and a PostGIS backend. There are 2 systems using the PostGIS database: one that is with Geoserver and one that is an old system that just uses the ...
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2answers
41 views
How to select by polygon in PostGIS with misaligned layers?
I have two polygon layers, one which defines subregions of the other. However, the layers do not line up exactly, so there are minor discrepancies along the edges. I would like to select all minor ...
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2answers
131 views
imposm: Failing to import OSM data to PostgreSQL
Somehow I can't import OSM data to my database. I'm using Debian, PostgreSQL 9.1 and PostGIS 1.5. The user root has been granted all privileges for the database osm.
Input:
imposm -U root -d osm -m ...
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1answer
44 views
PostGIS: Merge multiple table with same GID
I just imported some shapefiles with the PostGIS importer. Because several errors and issues I had to split my shapefile in multiple parts. Then I imported them one by one. I thought I can easily ...
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2answers
201 views
Create CMS system using Cartaro
The main objective for our project is to create a portal website in Drupal. On this website, people must be able to upload their geographical datasets (mostly shape files, but also xml files that ...
4
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1answer
59 views
Selecting surrounding states from a given state
I have a PostGIS spatial enabled table with the states in the US. How can I write a query selecting all touching states to a named state. Like this :
Select * from States Where geom touches (Select ...
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0answers
113 views
View PostGIS geometry in QGIS
I am a newbie to GIS systems so please be patient.
I have a PostGIS database set up with a spatial data table. One of the columns is of Geometry type and contains Points with SRID 4326. I want to ...
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1answer
63 views
pgsql2shp error when query is introduced
I'm trying to export a table from PostGIS using pgsql2shp. The basic query to export the entire table works fine using the following format:
"C:\Program Files\PostgreSQL\9.1\bin\pgsql2shp.exe" -f ...
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2answers
184 views
How can I get a shapefile from a postgis query?
My data is in a PostGIS database. I would like to generate a shapefile from a query. How can I do that?
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2answers
68 views
Is there a way to visualize a convexhull in qgis 1.8 lisboa?
There is no way to visualize a convexhull in qgis 1.8 lisboa?
I have tried following views in Postgis 1.5
I was told to use an id column to publish it in Qgis.
If you not use an id column, u cannot ...
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0answers
52 views
QGIS cannot view raster loaded to PostGIS through raster2pgsql
I tried to load a raster GeoTIFF image to a PostGIS database using "raster2pgsql" following the OpenGeo Suite Manual. The command I used is:
C:\>raster2pgsql -s 4283 -I -C -M "C:\Program ...
2
votes
1answer
53 views
How to create a buffer zone for notification
I am new to PostGIS.
I am working on a project, for this i need to find out abutter notification that generates a list of properties within the buffer zone from the selected property with user input ...
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4answers
127 views
How to convert multipoint layer to point
I have a Spatialite layer which is multipoint (following a QGIS Save As from shapefile). I need it to be PostGIS and POINT. I have tried ogr2ogr -nlt POINT and got 'new row for relation "xxx" violates ...
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0answers
56 views
How to Create database using OGC compliant geometries and Custom type Geometries?
I am interested in storing geometry attributes in a PostGis database, so that it would be OGC compliant, along with OGC compliant geometry types like point,line, linestring, etc. I also wanted to ...
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1answer
67 views
Missing function ST_Extent in PostGIS db
I hope you can help as I am tearing my hair out here. Do any of you elite geo peeps have any idea why some specific functions could be missing from my PostGIS install?
I am trying to use Mapnik with ...
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0answers
40 views
Table for feature layer in PostGIS database cannot be published and enabled on GeoServer
I have tried to publish a table for feature layer in a PostGIS database to GeoServer 2.2.5. The layer was added and published. However, the layer has got a yellow exclamation mark in the "Enabled?" ...
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0answers
43 views
How to import multiple shapefiles each with different source projections to postgis
I have a couple thousand .zip files each with a .shp, .dbf, .shx, and .prj inside them that I want to load into postgis. The problem is, they have many different source projections (each defined in ...
4
votes
1answer
70 views
What's the best way to run a visibility analysis in PostGIS 2?
I am looking for the best way to run a visibility analysis in PostGis 2, i.e. given 2 points and obstacle polygons, are these 2 points visible from each other ?
I did not find anything relevant for ...
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0answers
64 views
geoserver PointStacker
I'm trying to implement a clustering solution using geoserver (version 2.3.0 ), for this I'm using the Rendering Transformation Point Stacker and the clustering itself works fine.
However I have ...
1
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2answers
102 views
GeoServer Where clause filter
I use postgis, geoserver and openlayers for gis development.
I simply reach from goeserver to postgis table or view and show it with openlayers. but I need some filtering operation on my spatial ...
1
vote
1answer
70 views
How to visualize pgrouting query results in mapguide open source
I would like to make a spatial query using postgis 2.0 and pgrouting 1.05 then visualize results in Mapguide open source.Any suggestions?
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0answers
36 views
Problems combining (union) Multipolygons in geodjango
I'm using geodjango and postgis (1.x),
What is the best way to combine (union) a list of multipolygons.
in what i assume is rather inefficient i'm looping trough like this
combined = multipolygon
...
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vote
1answer
188 views
Unreachable vertex
I'm developing an application for academic purposes that mainly gives to the user a recommended itinerary for a previously introduced preferences (Gastronomy, Leisure,etc.).
For this purpose, I use ...
3
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0answers
71 views
building larger polygons from smaller ones *without* a common id in PostGIS
I am looking for a means, using PostGIS, of reconstituting a set of polygons from tens of thousands of smaller polygon 'pieces'.
This is a simplified example, with the pieces shaded:
Unfortunately ...
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1answer
50 views
PostGIS Manager Load Error
I am using the PostGIS Manager Load data to PostGIS tool on a Windows install and am getting the following error:
Something's wrong:
["'shp2pgsql' is not recognized as an internal or external ...
1
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2answers
71 views
geography_columns and geometry_columns purpose
Can anyone tell me what the purpose of the the geography_columns view and the geometry_columns table are used for in a PostGIS database?
My geography_columns view is empty so I can't see what the ...
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2answers
88 views
QGIS: using postgis can I define a layer using sql?
I have a vector layer (call it master) that is stored in postgis and consists of a number of line segments.
I also have a collection of sub layers that consist of subsets of the master layer. I can ...
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1answer
32 views
PostGIS: Querying a record table and explanatory table
Basically I have two tables one containing a collection of records and one table that contains extra info about features in the first. i.e
Records Table:
GID
SITE
SPECIES
GEOM
and the second table ...
2
votes
2answers
86 views
How do I plot data stored in an attribute table (really in a database) in qgis
I have a csv of UK postcodes from Ordnance Survey that looks like
SE1 0AA,10,531869,179427,E92000001,E19000003,E18000007,E09000028,E05000536
When I import to QGIS using 'Add Delimited Text Layer', ...
1
vote
1answer
136 views
Count Points in Polygon with Postgis
I've got a simple problem: I want to count the number of points within a set of polygons.
I have a SQL already but it only gives back the gid of the polygone that actually contains points.
My ...
3
votes
4answers
122 views
converting oracle geometry to postgis with 3d data (wkt?)
I am converting Oracle spatial database to postgis. Most of of the spatial data is 2.5d. Meaning we have a Z-coordinate which indicates the depth/height of the element compared to soil level.
Getting ...
